SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c270898a4f386a5ba98d7683ef9f40dbc97e15f233f3e53cb8df15561edeea67' 
  AND token = 'qgQqYu6+/aMFPzgTQjjyetGzv4o4ftsm/PFKzkPsz1o=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00059

JSON explain

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