SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = '422e6a9dc18111f980a9362035fc41a49f6ab3644546fb96083765c81c53ec0b' 
  AND token = '0FJcENvkvAeJIDU1gGSGgaJd9ts13zehlqho6Bv/WVk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00044

JSON explain

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