SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3442a086242b1668c1a64ceb66fc2b3979804faf4aecd9a587990a98d2943710' 
  AND token = '6RxaFqsf7OCe1vdLNtJrEaOaZWvWlFi1Irqcfv3Ugc8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

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