SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e03ca701add7981fd14ae09068811ec452aeda0d2c8ac541af659fdeb9b94ba3' 
  AND token = 'Nm3LcU78B8OWh25clgVnVUfyELTrNcsMil/7HtkwFEQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

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