SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'fe17a396506f5cf6c1b44096817bc9b875ce6e9c7e3ffadec5842f14195abd02' 
  AND token = 'jg07C0AoQ7q+KG/Lpc0vYv/CUjnuki1VMrobbTuUYGk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}