SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3cca5eea769cc1797cbef342be090e47dcfe845330475220027a02c04016bd1c' 
  AND token = 'P9idzjPJCX7y3Zz/geA3LAdqHE/4BJ8DzJK7wcmUajE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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