SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'cc49f49ff7344f7b8bee139c1bc154a90e8e531ac691bd4598a812d66fa97c1a' 
  AND token = 'FnrmbZrpg0JOspdwlVvHvSF5l62/nWSZFHNE4ihBCI8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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