SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '440e0edc06a8974316875d35dfde42443cc19f6e8ef31625bcb3723a31f9609a' 
  AND token = 'myT8yuIflEd82UoohC/9n+T99NiZBpEXH0vFHXNns1A=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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