SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = 'd9017193d0b87f717226c536b5a3561503f77eb6b7edb9697e105063ac6a04b0' 
  AND token = '6u/y2Lbhbd/D5URimtUEIG+QF0vXHSGAmIDWhZp/Qkw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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