SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '8ec6741f0d646481fd2f613513cee64b0cc385b86a561957033bdb4f9ecb0b96' 
  AND token = 'AvEFghBAcv3RL+lY+ilXOO6s17zUtWwnWXx2oLtmHWw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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