SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0a66e83585c093c70d4611fb30ce776cccd0e7ed489bf791db0f62aee9a41aa0' 
  AND token = 'Viqjr/YI5+bVr4Qe5chTnIwqPGyTImQh7BTI04HNmlI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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