SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '66378d1da66fbd518d584407f77be6797474b82e5945394834fe0f821416dadc' 
  AND token = 'ksG0LpUkRWJJai1mx74wXv4KSuJdu8sTvEinX+syWmQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

JSON explain

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