SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '287c908146bb8f31c963f271ad3e6b2b144a954f2a5bac35f2ab5ded1265e1a6' 
  AND token = 'PicDmvmPJDw0hamMwaanmGFkaaAW21GGPZDEktCTbuQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00041

JSON explain

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