SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2f9608eafefbd87f5a937706ce0726d7d18261d29dafc3195b84e1e9a18bf149' 
  AND token = 'ATgjS3xyTUtV/JLp4EOr8qR6obpnek9LYaowTyJftYo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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