SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e4dc8bafe73e6c33dc9800cb4ffbce5fad11177f19ecc1960c8d1af2d43dcd9d' 
  AND token = 'IMTQdgycIXgXY7U2ycw1HjG2GsKPGCF0Mfku4Mq23tU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00049

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}