SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '58663a5b51c988b26bb3b1dc433d2dc75c656289919eee1164b48929e7bfce45' 
  AND token = 'MDEUdAeAV2s5liR9ofhsS1HVzkC2gHbWvPvmVyCYG8I=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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