SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ea00972d2c46bf6dfaa24fd4d992c5798989562f2d0a6df61725ae3506dd9619' 
  AND token = 'tWe/6Hjkop09bNN/0g1eU8lXZy7RVRqwPYVhDRyUuqA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

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