SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f7efb504cadd2169d89f8a9d3565bcf21239b9a2c1356dfd0ad566b1b9f6bd9d' 
  AND token = 'EZLr+lwPpHaZvv/qc31CB3TYktR6xCKkZADumwvQxLU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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