SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '405fbbf79c6b2f1618d8aee57a846d6c21941b3bdc4c6d3fcb695b4f69c143d0' 
  AND token = '7Jp0Iz/hGTDmVAVvDFf+0MvmLTtP9k7+ozktgI3Xh18=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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