SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'e41563ab65c91327d232e0528446f7e93824a82eca71462d5f6ce1cbc108e936' 
  AND token = 'aiscV0N6RrozsVR1UcMszEuXWVL5MSZ76hJkN2rACpQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00055

JSON explain

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