SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'fd981f9abc6795e0ddba7bfaa1104994d07664492fdec554d98a33432a2bf6dc' 
  AND token = '2TC2jQ6+v2iA5wqkYCRhPKBSIC2f1vUka2h/ogt7STw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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