SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '985579e15cd5e44ed4febcb716e7d60d3ebcdd23b4b696b2ae4249bbe4a2b67e' 
  AND token = 'L87DTAk903tTAxd4UpTcaVZXGM5vStiBVbZjK99+Ftw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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