SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'fecfe771c0a0576ca46aba4865d11dba33991a4c3cacfa3464593ca8cc95f87e' 
  AND token = 'V/ST2z2xIli2fi2oo8Siw2FCVNFYqOtvaGilmrI1ZL4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00043

JSON explain

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