SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'e455ec3f60c3707b2fc28ed7d5eb8534e5664a2d7c2e57da9c4313e04fcbf6ec' 
  AND token = 'gjh6e7QQYO96GBu64/CKZxicfYP5RAvrSKlF+dHVEJg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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