SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '796f813f42910d85d7fc5d8bbcca75795f032c5b7933634ba6996129885c1920' 
  AND token = 'i+n/bZtbxjfga3jj37KfupDhlDAMsy9gtjX2Ev8vHkw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00044

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}