SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e77f9f2f9290dca17f8276e15b61a91f20b33e84d370e8768e0195fb5eddf1a1' 
  AND token = '+PTbIhKxS0ky4Vn5MSOP3I4m5KQvbqkvrtXoWLipbHw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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