SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ee1e18d980501a9478ca036f8370eaa18f4052a8aba94af943d9f639123ab156' 
  AND token = 'gwmQqTy3pyNDCGlmrcjo3dlGKiGkd+mb9vLHJIRoEY4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00041

JSON explain

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