SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b0a441223e6bd392118aaa643695179283f2bcfba4e1a7e0ed338ec9901df941' 
  AND token = 'I8HR4QgcOPKplr1HLAUDvSUYFQrbG6HMFiYpfWc3ESw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00045

JSON explain

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