SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'dbdfd38d1cc70a79ff9b9a8999c1cf5a206232b649c47d974482cdf9f9a60b5b' 
  AND token = '5elC4P9o5JQtXiTfldFPVlhh2ftEMsfTLkK7s4z4i+0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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