SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = 'b7825afe215a2f047f608e1d50e593d4a65cf76fb353a23f3ae1b7b705a94eba' 
  AND token = 'RKItGDVEyuZyIz1zdXGpKW+140x8qk+3aIKIezmqY8Q=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00045

JSON explain

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