SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '00498ddb0745bde5642c8429a733560044940408181d046716fd1be4c9df03bd' 
  AND token = 'fpT6ar4uBrpyUuElDp9cqpdxYunOnc4nvOROFNJNee8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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