SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f6045036b406d3e01a49d8bb90083cf6906ff862a1eb926c68248e72e0a4509a' 
  AND token = 'yMhvDrk4J9oCNMnPaS4OQYOEr9s8eeX5Nsg52e5kqBo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00042

JSON explain

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