SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '6d8128ae1bae8294433a3d103b7c753f00fcf2f2fde60d434e068c1ab03229b2' 
  AND token = 'DxZ1773brxW++NJwzHzjO92DGM2ReAVCz0E1wx7s8Rw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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