SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = '4cbf7ad16a5fb7c12d128ff05a12b60aee1ce98db90e3a708d96fe6d0e1c9a11' 
  AND token = 'nFUjWfEVgkkXbKOmf5rE1VfHPmW1VaA+hrAU2dzGuWI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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