SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e076354d37e340510f55ff6ca8b44d662f78207ef6bb26908d2b00b463606276' 
  AND token = 'ij3rA4xTHrI8fmm2cjQSPd5oF/r5cE/thMMpjV3iz38=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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