SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '259fbec4886a337cad0579f567fde24cf906b991a8aa7996b61cda44980e338d' 
  AND token = 'pyMCyrix+vw/dr2JQ2Ul8kvqpMzZ5cCDOI1T3zlVWPw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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