SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'cf64f9a1a6967fd2b1c973e0971623751cf4e315032402cd3dd3295cd8aedc6b' 
  AND token = 'AGFNTBvPKvHIegcGhBk+FeDbcV/CsfyDdxIXfIDAiYE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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