SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = '76993fbd48b7f20e9997e4a9b7c1da369edfeee0678aaf4c5cfdcc5431545bb5' 
  AND token = 'ChUPmBvPrm0Sbg/quc5RoQ3hHp4CXlTfYVKQ9rYJc2Q=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00039

JSON explain

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