SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '09b12610fcf9d7585e233ce36057078dd6228112e2bd88c5acd9b666e419a6bc' 
  AND token = 'u3oG4FR8BrO+nXYbgZ89j/sKnV2FvVufvvMj2Oix+tk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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