SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8f0d1d36957b10b50a9e0ecfd183c707881c06487526d22bb3e52be15f73541b' 
  AND token = 'X3NUth4/fXPPeZdUDQTVkJLCdKZ+AoJWELieQMRYWDo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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