SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8cb9993d6049e6b5a1eb7310294a468e591819258c55c13536bc76f5841fb3b3' 
  AND token = 'pSB/PlHA1y/yU5n7CxWMeqgrHMuhroZVOtTbGmLVWhs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00047

JSON explain

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