SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '84ecc01bba4e5c51c1e0c15b14194a722ad6897844f9066f5e1217fa4b45bf8a' 
  AND token = 'jbTBmQCzvWvp1UgVkank3Qr5MyVHJnLbzY/q6vN3sZQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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