SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7a6c8525bc855a8b2dad9f8f06fa4b3830820d2b47581dacb9b4ed9d4eca4ad9' 
  AND token = 'uHVsyNEDTYtRANyQTwe0gJiwcxaeKVFqjDmb8WOi2LM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00016

JSON explain

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