SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '53747413e3f88d521891fd9dd0366808f27d5ecebd8f13225f2564e9568b8650' 
  AND token = 'SFnj6cKaRBxaELDhX0CRdAA0aaKH5mInvSFJ7nMoWrw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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