SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = 'bf62e0b456f78a1720fec0726391bac86616dbcd455fcd5bee340167dd4b05f1' 
  AND token = '4jDd0YKL9JB/5fciTi4FIR2DKPBLngwnQBzY0A+aCOI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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