SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a8047f42f30a47581ec9a4bde7c9b1ce000d36bc0dbf6d24ee296aed9f1819d1' 
  AND token = '+eeSSnLxPtVhwXsn6mH/BCxnulczBiT/ML4m+HyLAvE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00040

JSON explain

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