SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '92bd06c22a2c7a429d883a1488c2e083ecde6ccc2349c36e70130638f1849522' 
  AND token = '2IaNpKc1fjFq5O9KaZFMznTn953rRGmFsWF+ud44fek=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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