SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b09a38ab2fb07c5b341f309ee9a91998f91b30205014d21f38076012466222d1' 
  AND token = 'uYnVTj62z/lgwAoiIn9Msd0KSSb4zwcW2HvN3tlwe8E=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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