SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a0d659564364432234e77a5ba0ea56463ad83510f4a9534ba1f1d7ccdc6bec68' 
  AND token = '95+PuapPAZYiWAL77rULGlvCykp8vJ5fa3IdT2Ix14k=' 
  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"
    }
  }
}