SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = 'b6a79509b531f65e2cf3494b21965a0b3e24c410679a3c92aa56b8fd4128e032' 
  AND token = 'dzzfXTRpKcQTq6rEQKRXx9xwXr1K+IJ9km6C4JyU+l8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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