SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'cf0c7f66698460a591211804fccbc3e26e39469196d4b7358d25ee61f0093c33' 
  AND token = 'PFKPKN+BTMWOqTSRus/KaaYPZGhGxyWbeX+gFUVxuDk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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